Most hand-held electrical devices having a handle grip use a trigger switch to activate the device. Hand-held tools having electric motors, or "power tools," for example, use large trigger switches to activate the tool's motor. These trigger switches provide desirable tactile feedback to a user: i.e., the force needed to actuate the switch is greater prior to switch closure, with a sharp drop-off in force after switch closure providing tactile feedback to the user that the switch has been activated.
These trigger switches generally have a limited useful life. The life of most power tools is based on the life of their motors. The life of these motors is less than that of the switches. Therefore, trigger switch failure in power tools is relatively infrequent.
Electrical devices with few or no moving parts, i.e., "electronic devices," however, often have a life greater than that of power tools. Hand-held electronic devices using trigger switches should use switches having a lifetime at least equal to that of the electronic device. For example, a bar code scanning device will typically be activated approximately 2,000,000 times or more during the device's lifetime. A switch capable of over 2,000,000 actuations is therefore necessary. These long life switches, however, have a relatively flat force versus actuation distance curve, and thus provide poor tactile feedback. Users are unsure whether they have activated the switch after depressing the trigger. Switches having desirable tactility such as those used in power tools typically have a life of approximately 200,000 actuations.
If these desirable tactility switches are used in bar code devices, the switches must frequently be replaced. Most electronic devices incorporate the trigger switch within the device. Therefore, when the switch fails, the device must be serviced. This service results in downtime of the device and the expense of repair, and also requires a user to purchase additional devices to compensate for this downtime. Overall, switch failure in electronic devices results in increased costs, decreased efficiency and loss in productivity.